The composition and structure of rotiferan and crustacean communities of the lower rio nhamundá, amazonas,Brazil

The crustaceans and rotifers of 17 samples from the plankton and 3 from the littoral from lakes of the lower Rio Nhamundá, an affluent of the Amazon were studied.

145 taxa of rotifers and 46 of crustaceans were found; two rotifers and three crustaceans are new to science: Keratella americana nhamundaiensis, Euchlanis triquetra var. nhamudaiensis, Echinisca superaculeata, E. sioli, and E. mira. In the taxonomical part 24 rotiferan and 22 crustacean taxa are described in more detail, drawings of them given, and partly remarks made about the geographical distribution.

In the biocenotical part the conditions of dominances were studied: Brachionus zahniseri and Keratella americana within the rotifers and Bosminopsis deitersi and Oithona amazonica within the crustaceans are the dominant species in the pelagial. In the littorial Synchaeta stylata and Stre‐blocerus pygmaeus were found to be dominant.

The species diversity and also the evenness is higher within the rotifers than in the crustaceans. By means of an index of similarity dendrograms were drawn where groups of lakes can be differentiated by using the similarity between the crustaceans. The proportion of neotropical species in relation to pantropical and cosmopolitical species is lowest in the rotifers, higher in the cladocerans and highest in the copepods at 100%.     

The language of systematics,and the philosophy of ‘total evidence’

This contribution analyses the primacy of classification over generalization, and the philosophy of total evidence that emerges from the relation of homology to character statements. Primary conjectures of homology are basic character statements, i.e. statements that predicate properties of organisms, properties that are instantiated by those organisms and/or their parts. Secondary conjectures of homology are embedded in a second‐level (metalinguistic) discourse that turns on the coherence or incoherence of those basic character statements relative to a hierarchy. The coherence or incoherence of character statements is a logical relation between statements, not a causal (historical) relation between organisms. The choice of the hypothesis of relationships that is supported by the largest set of coherent basic character statements is based on the empirical presupposition that the properties referred to by the set of coherent character statements are grounded in causally efficacious relations of inheritance and ontogeny, and co‐instantiated because they are inherited through common ancestry (Hennig's auxiliary principle). Unless that empirical presupposition is causally grounded, phylogeny reconstruction is of an inherently probabilistic nature, whether under parsimony or other models of analysis. The causal grounding of a coherent set of character statements typically seeks a link between character statements and causally efficacious generative mechanisms for morphological characters (as is defeasibly indicated by topology and connectivity), or secondary structure information for molecular characters.     

The Evolution of the idea of homeostasis: Determinism,stochastics, and chaos–self-organization

Homeostasis is a basic concept in investigating all living systems. Homeostasis and life are synonyms to a certain extent. The concept of homeostasis has been studied and developed for more than 150 years; however, only the 21st century brought us close to understanding homeostasis as a state of a biosystem and a continuous process. The chaos and self-organization theory (CSOT) proves that the conventional views based on determinism (functional analysis) or stochastics (when stochastic uncertainty or certainty occurs) cannot describe homeostasis as defined by W.B. Cannon and his followers. The new CSOT shows a clear boundary between determinism, stochastics (and deterministic chaos), and third-type systems, which have five special properties (principles of self-organization) and can be described in terms of quasiattractors. Kinematics is understood as the motion of quasi-attractors in the phase spaces of states. Complexity is introduced as the rate of evolution of complex biological systems, differing from the definition by Prigogine–Glansdorff. At the same time, concepts of uncertainty of the first and second types and an analog of the Heisenberg calculus are introduced for complexity. According to these concepts, complex biosystems are transferred from the area of traditional science to a new area of the theory of chaos and self-organization.     

The yins and yangs of ceramide

Since their discovery over 100 years ago,sphingolipids have caught the eyes and the imagination of scientists.Modern science has made many new insights on the cell biology and day-to-day functions of many integral sphingolipids,especially those of ceramids.Ceramide is recognized as a vital second messenger in the signal transduction process mediated by receptors of many cytokines and growth factors.A great part of our current understanding of ceramide has been achieved from apoptosis-related studies,however recent data in the fields of immunology,endocrinology and neurobiology,also suggest a fundamental involvement of ceramide in the onset of diseases.Therefore,understanding the diology of ceramide could be a key to unraveling many biological mechanisms and provide information for the treatment of some common diseases.     

The 8~(TH) Conference of The Chinese Society for Cell Biology (CSCB) Nanjing, November 2003

The 8~(th) conference of the Chinese Society for Cell Biology will be held in Nanjing,November 2003.The conference iscalling for abstracts of original works on all aspects of cell biology.The conference will invite distinguished scholarsto give talks on cutting-edge topics in cell biology research.Programs will include plenary lectures,platform and     

Parasites, flies and men--21st Meeting of the German Society of Parasitology in Würzburg

The German Society of Parasitology (Deutsche Gesellschaft für Parasitologie) was founded in 1960 and its 21st biannual meeting took place in Würzburg, Germany, from March 17 to 20, 2004. Whereas interim meetings that are being held every other year focus on specific topics of parasitology, such as the symposia on "Life in Vacuoles" in 2003 and on "Immunomodulation by Parasites" in 2001, the general biannual meetings cover a wide range of topics. This year's meeting at the University of Würzburg was organised by Klaus Brehm and Matthias Frosch (both at the Institute of Hygiene) and Heidrun Moll (Institute for Molecular Biology of Infectious Diseases). It was attended by more than 500 scientists from 16 countries who presented 181 research projects dealing with the topics defence mechanisms and immunology, genomics and proteomics, epidemiology, cell biology and biochemistry, chemotherapy and vaccines, parasite classification and morphology, vectors, intermediate hosts, and veterinary parasitology. In addition, six plenary lectures highlighted the subjects of comparative nematode genomics, cell biology, immunology, and parasite eradication programmes.     

Jiuzhaigou, The World Natural Heritage and the member of CBRN

For thousands of years, Jiuzhaigou was hidden in the mountain ranges of the plateau northwest of Sichuan. It was left to the hand of nature and human activities seemed insignificant. For a long time, there were only narrow paths for horse travels and the local Tibetans lived a self-sufficient     

The Role of Zoos in Modern Society—A Comparison of Zoos' Reported Priorities and What Visitors Believe They Should Be

Modern zoos are required to fulfill a growing number of responsibilities including scientific research, wildlife conservation, public recreation, and education. With so many roles and responsibilities and limited funds, zoos have to prioritize their activities in relation to their own specified goals, objectives, and mission statements. Given their desire to nurture community relations and educational opportunities, it is important to determine the extent to which zoos are prioritizing their activities, according to visitors' expectations. This paper presents empirical research of a two staged mixed-methods investigation into zoo priorities from both zoos' and visitors' perspectives. The first stage involved an online questionnaire to which more than 190 zoos across 52 countries reported their priorities and activities. We then undertook in-depth case studies in nine institutions, enabling direct observation of each site within its context, including face-to-face visitor interviews. Our research contrasts the priority given to zoo activities from each perspective and indicates that educating visitors, including school children, is the highest priority activity from the zoos' perspective and that of their visitors. The findings also show that visitors place high value on learning about actions they can take to help conservation efforts. Some inconsistencies between zoos' and visitors' priorities were also evident, such as the different emphasis placed on viewing endemic species, and zoos being a place for people to relax and socialize. The implications of these findings are discussed.